3942748
Rocker Lever
Cummins®

Introduction

The Rocker Lever 3942748 by Cummins is a critical component designed for use in commercial trucks. It plays a vital role within the engine’s valve train mechanism, contributing significantly to the vehicle’s overall operation and performance. This part is essential for the engine’s ability to efficiently manage valve operation, which is crucial for engine functionality ¹.

Basic Concepts of Rocker Levers

A rocker lever, also known as a rocker arm, is a pivotal component in an engine’s valve train. Its primary function is to transfer motion from the camshaft to the valves, allowing them to open and close at precise intervals. This transfer of motion is achieved through a rocking motion, hence the name. The rocker lever amplifies the camshaft’s motion, ensuring that the valves open sufficiently for optimal engine performance. Its significance lies in its ability to facilitate efficient valve operation, which is fundamental to the engine’s combustion process ².

Purpose and Function of Rocker Lever 3942748

The Rocker Lever 3942748 is specifically engineered to interact with the camshaft and valves within the engine. It receives motion from the camshaft and transmits it to the valves, causing them to open and close. This part is designed to ensure that the valves operate with the correct timing and force, which is vital for the engine’s efficiency and performance. By precisely controlling valve operation, the Rocker Lever 3942748 contributes to the engine’s ability to maintain consistent power output and fuel efficiency ³.

Key Features

The Rocker Lever 3942748 is characterized by several key features that enhance its performance and durability. Its design incorporates materials that are resistant to wear and high temperatures, ensuring longevity under the demanding conditions of commercial truck engines. The part is engineered with precision to ensure accurate valve operation, which is critical for engine performance. Additionally, any unique attributes, such as specific coatings or treatments, are aimed at further improving its resistance to wear and corrosion, thereby extending its service life ⁴.

Benefits

The use of the Rocker Lever 3942748 in an engine setup offers several benefits. It contributes to improved engine efficiency by ensuring precise valve operation, which is essential for optimal combustion. The part’s design and materials also enhance the engine’s reliability, reducing the likelihood of failures related to valve train components. Compared to alternative designs, the Rocker Lever 3942748 may offer advantages in terms of durability, performance, and ease of maintenance, making it a valuable component in commercial truck engines.

Troubleshooting and Maintenance

Common issues with the Rocker Lever 3942748 may include wear, noise, or failure to operate correctly, which can affect engine performance. Diagnostic tips for identifying problems with this part involve listening for unusual noises from the valve train, checking for proper valve clearance, and inspecting the part for signs of wear or damage. Maintenance practices to ensure optimal performance and longevity include regular inspections, proper lubrication, and timely replacement of worn components. Adhering to these practices helps maintain the efficiency and reliability of the engine.

About Cummins

Cummins Inc. is a global power leader that designs, manufactures, and distributes a wide range of power solutions, including engines, filtration, and related technologies. With a history spanning over a century, Cummins has established a reputation for quality, innovation, and reliability in the commercial truck industry. The company’s product range includes engines and components designed for heavy-duty applications, reflecting its commitment to meeting the demanding requirements of commercial transportation. Cummins’ reputation is built on its ability to deliver high-performance, durable solutions that enhance the efficiency and reliability of commercial vehicles.

Compatibility of Rocker Lever Part 3942748 with Cummins Engines

The Rocker Lever part number 3942748, manufactured by Cummins, is designed to fit a variety of Cummins engines. This part is integral to the valve train system, ensuring proper valve operation and engine performance. Below is a detailed overview of its compatibility across different engine models:

ISC Series Engines

• ISC CM554
• ISC CM850

The Rocker Lever part 3942748 is compatible with both the ISC CM554 and ISC CM850 engines. These engines are known for their robust design and are commonly used in heavy-duty applications. The rocker lever ensures smooth and reliable valve actuation, contributing to the overall efficiency and longevity of these engines.

ISL Series Engines

• ISL CM554
• ISL9 CM2150 SN

The ISL CM554 engine also utilizes the Rocker Lever part 3942748. This engine is part of the ISL series, which is recognized for its high power output and fuel efficiency. The rocker lever in this context is crucial for maintaining the precise valve timing necessary for optimal engine performance. Additionally, the ISL9 CM2150 SN engine, while slightly different in specifications, also fits this rocker lever, ensuring consistent valve operation across the ISL series.

QSC Series Engines

• QSC8.3 CM554
• QSC8.3 CM850 (CM2850)
• QSL9 CM554

The QSC8.3 CM554 and QSC8.3 CM850 (CM2850) engines are designed for applications requiring high performance and reliability. The Rocker Lever part 3942748 is engineered to fit these engines, ensuring that the valve train operates smoothly and efficiently. The QSL9 CM554 engine, part of the QSL series, also utilizes this rocker lever, maintaining the same high standards of performance and durability across the QSC and QSL series.

This compatibility ensures that the Rocker Lever part 3942748 can be used across a range of Cummins engines, providing a reliable and efficient solution for maintaining the valve train system.

Role of Part 3942748 Rocker Lever in Engine Systems

The part 3942748 Rocker Lever is an integral component in the operation of various engine systems, primarily within the valve train mechanism. This component works in conjunction with several other parts to ensure the efficient and precise operation of the engine’s intake and exhaust valves.

Interaction with the Valve Train

In the valve train system, the Rocker Lever, specifically part 3942748, is responsible for transferring the motion from the camshaft to the valves. The camshaft, driven by the engine’s crankshaft via a timing belt or chain, features lobes that push against the Rocker Lever. This interaction converts the rotational motion of the camshaft into the linear motion required to open and close the valves.

Coordination with Pushrods and Lifters

In overhead valve (OHV) engines, the Rocker Lever is typically actuated by pushrods. These pushrods connect the camshaft-mounted lifters to the Rocker Levers. When a cam lobe pushes down on a lifter, the motion is transmitted through the pushrod to the Rocker Lever. The Rocker Lever then amplifies this motion, ensuring that the valves open sufficiently to allow the necessary airflow into and out of the combustion chamber.

Integration with Overhead Camshaft Systems

In engines with overhead camshaft (OHC) configurations, the Rocker Lever may be directly actuated by the camshaft without the need for pushrods. Here, the Rocker Lever plays a direct role in translating the camshaft’s motion to the valves, often with the assistance of bucket tappets or roller followers to reduce friction and wear.

Role in Valve Clearance Adjustment

The Rocker Lever also facilitates the adjustment of valve clearance, a necessary maintenance procedure to ensure optimal engine performance. By incorporating adjustable components within the Rocker Lever assembly, mechanics can fine-tune the gap between the camshaft and the valve, accommodating for wear and ensuring precise valve operation.

Contribution to Engine Efficiency

Efficient operation of the Rocker Lever is essential for maintaining engine performance. It ensures that the valves open and close at the correct times and with the appropriate force, directly influencing the engine’s power output, fuel efficiency, and emissions. The design and material of the Rocker Lever, including part 3942748, are engineered to withstand high stresses and temperatures, contributing to the durability and reliability of the engine system.

Conclusion

The Rocker Lever 3942748 by Cummins is a vital component in the valve train mechanism of commercial truck engines. Its precise function in transferring motion from the camshaft to the valves ensures efficient and reliable engine operation. The part’s design, featuring materials resistant to wear and high temperatures, enhances engine performance and durability. Regular maintenance and proper troubleshooting are essential to maximize the benefits of this component, ensuring optimal engine efficiency and reliability.